's Big 100 database reveals the medical device companies that post the highest net profit margins – and the lowest.

The current economic downturn has put paid to the notion that healthcare markets are recession-proof, with the formerly high-flying medical device industry struggling along with the rest of the business world.

But for some companies, the bad economy proved less of an impediment to profitability than for other, last year in particular.

Firms including American Medical Systems (NSDQ:AMMD), Intuitive Surgical (NSDQ:ISRG) and Synthes all managed to maintain healthy net profit margins. Others, such as Biomet, NuVasive (NSDQ:NUVA) and Wright Medical (NSDQ:WMGI), fared worse.